Boiler construction



May 8, 1945.

J. W. THROCKMORTON ET AL BOILER CONSTRUCTION Filed Jan. l, 1944 Patented May 8, 1945 norma coNsraUcrro-N John w. 'rhrockmm-ton, Wilton, and John s. Wallis, Darien, Conn., assignors to Petro-Chem Process Company Incorporated, a corporation of Delaware Application January 1, 1944, Serial No. 516,630

4 Claims. (Cl. 122-338) This invention relates to improvements in boiler construction, and refers more particularly to a cylindrical or multisided upright furnace in which the source of combustion gases is located in the ibottom and are discharged from a flue at the top.

'I'he construction aords a simple, convenient,l

Referring to the drawing, the furnace proper comprises a cylindrical shell l0, supported by columns or standards Il. Surmounting the cylindrical shell is a flue l2 fitted with a chimney or stack I3. The ue is held in place on top of the combustion chamber or furnace by means of an angle ring I4 which not only supports the flue, but also holds and carries the weight of the vertical reservoir l5.

The steel shell or casing of the furnace is lined with a layer of insulation I6 and a layer of refractory firebrick l1. Extending through ports or holds in the floor of the furnace are a pluthan in a horizontal position. transversely across the top of the furnace, and the location of the downcomer pipe centrally of the combustion space instead of outside of the furnace wall. By these changes the size of the top reservoir or drum can be made considerably smaller, reducing expense without sacrificing efliciency. The vertical position of the drum also gives better assurance of a substantial body of waterl as a source of supply for the water column maintained in the stalled in the open without the necessity of a boiler house or other enclosing structure, and one which may be easily and inexpensively cleaned and repaired.

In the accompanying drawing which forms a` part of the instant specification and is to be read in conjunction therewith, and in which reference numerals are used to indicate like parts inthe various views,

Fig. 1 is asectional side view of the boiler and furnace construction,

Fig. 2 is a view taken along the line 2-2, Fig. 1,

Fig. 3 is a plan view, taken from above, of the lower manifold or mud drum.

rality of directional burners I8 which may be adjusted to direct the combustion gases so that the heat is uniformly distributed throughout the furnace and over the surfaces of the tubes or heat exchange elements.

Although but two burners are shown, it is understood that any number'may be used to supply the necessary amount of heat. In place of burners itis contemplated that the combustion gases may be supplied from any type of fuel, either coal, gas or oil.

Below the furnace floor is supported a circular manifold or mud Adrum i9, which is connected to the reservoir or steam drum l5 by a plurality of heating tu-bes 20. These tubes are connected into the top of the manifold I 9 and are positioned vertically around the combustion chamber adjacent its inside Wall. Their upper extremities are connected into the periphery of the steam drum at a height about midway between the top and bottom.

The steam drum or reservoir is equipped with a water inlet pipe which enters somewhat above its mid-portion at 2|, and terminates at the bottom of the drum near the draw-oil' line 22 which serves as a downcomer pipe from the reservoir to the lower manifold I9.

Into the top of the steam drum is connected a steam outlet pipe 23, and centrally of the drum is a manhole or clean-out connection 24. At 25 in the upper part of the drum is a connection for a safety valve, and at 26 is a connection to a water column.

In the bottom of the drum are vertical baffles 21 which prevent vortexing ofr the Water in the location of the withdrawal through the downcomer pipe 22. At 28, in the sides of the furnace, are shown observation ports.

' The downcomer pipe 22 has connections 29 with the mud drum or manifold i9, and a connection 30 with a Water column, similar to that shown at 26 near the top of the steam drum. A

blowdown connection 32 and controlled by valve 33 is connected into the bottom of the water column 22.

In the upper portion of the combustion chamber or furnace is arranged a baille which has an"y upper cylindrical portion 3l, and a lower conical portion 3|a. The apex of the depending cone 3Ia is truncated and open to permit passage of the downcomer pipe 22 therethrough.

From the construction the operation of the boiler is obvious. Combustion gases produced by the burning of fuel in burners I8 pass upwardly through the cylindrical furnace and are diverted outwardly by the conical portion 3ia of the baille. In the lower portion of A`the furnace the heating tubes 20 are subjected principally to radiant heat, and it is in this zone that a major portion of the heat exchange between the combustion gases and water passing though the tubes is effected.

Cone Sla causes the gases to be diverted outwardly into the annular space formed between the cylindrical portion 3i of the baille and the inside wall of the furnace. The heating tubes 20 extend through this annular passageway and in this portion of the furnace the heat exchange elements or tubes are equipped with extended surface in the form of radial ilns 20a which extend longitudinally of the tubes and are welded to the tubes to produce eillcient heat exchange between the convection heat of the gases and the fluid passing through the tubes. As this annular passageway receives primarily only convection heat, the efciency of the tubes is considerably augmented by the extended surface. Above the passageway the tubes are shaped inwardly and connected to the steam drum near its mid-section. The combustion gases after passing through the annular space, between the baille and furnace wall, pass upwardly through flue i2 over the sides of the steam drum and out through chimney I3.

The water to be heated in the boiler and from which steam is to be generated is supplied through inlet pipe 2| by means of which it is delivered into the bottom of the reservoir in the throat of the downcomer pipe 22. Its course is downwardly through the downcomer pipe, thence through connections 29 into the mud drum or lower manifold I9, where it is distributed to the vertical tubes 20. Rising through these tubes, the water is heated by the combustion gases and is discharged into the steam drum where unvaporized liquid returns to the downcomer pipe while the steam is drawn off through outlet 23. Liquid discharged into the upper reservoir through heating tubes 20 is prevented from swirling or vortexing about the downcomer pipe by means of baflles 21.

The downcomer pipe being located within the baille for a considerable part of its length is subjected to somewhat lower temperatures than the heating tubes arranged about the surface wall of the furnace, thereby assuring relatively rapid circulation due to convection currents in the system. In other words, that portion of the downcomer protected by the baille receives considerably less heat than the heating tubes in the upper portion of the combustion chamber; likewise that portion of the downcomer below the baille being located centrally of the furnace and having comparativelyless exposed surface than the columns of water in the heating tubes transmits less heat to the fluid passing therethrough. Furthermore, the directional burners are arranged to project the combustion gases outwardly against the heating tubes, where the highest temperatures are concentrated.

'I'hus it will be seen that relatively rapid convection currents will be created in the system due to the severe heating of the bank of tubes surrounding the combustion space where the rising fluid flows, the more moderate heating of the column of liquid in the downcomer and the maintenance of a liquid body in the steam drum protected from extreme heat by the baille and supplying the coolest liquid in the boiler to the down-flowing column in the downcomer.

As many possible embodiments may be made of the invention without departing from the scope thereof it is understood that all matter herein set forth or shown in the drawing is to be interpreted as illustrative, and not in a limiting sense.

From the foregoing it will be seen that our invention is one well adapted to attain all of the ends and objects, together with other advantages which are obvious and which are inherent to the structure.

Having thus described our invention, we claim:

1. A boiler construction comprising a vertical chamber having a source of combustion gases in the lower portion thereof, a flue at the top, a baille intermediate the flue and combustion gas source causing outward divergence of the gases leaving the chamber, a cylindrical reservoir vertically positioned in the upper part of the chamber above the baille, a lower manifold adjacent the bottom of the chamber, heat exchange elements surrounding the chamber and adjacent its inside wall surface connecting the manifold and reservoir, a downcomer positioned centrally of the chamber connecting the reservoir and lower manifold, a fluid inlet to the reservoir, and a vapor outlet therefrom.

2. A boiler construction comprising a vertical chamber having a source of combustion gases in the lower portion thereof, a flue at the top, a baille intermediate the flue and combustion gas source causing outward divergence of the gases leaving the chamber, a cylindrical reservoir vertically positioned in the upper part of the chamber above the baille, a lower manifold adjacent the bottom of the chamber, heat exchange elements surrounding the chamber and adjacent its' inside wall surface connecting the manifold and reservoir, extended surfaces on the heat exchange elements in that portion of the chamber wherein the path of the combustion gas is outwardly diverged by the baille, a downcomer positioned centrally of the chamber connecting the reservoir and lower manifold, a fluid inlet to the reservoir, and a vapor outlet therefrom.

3. A boiler construction comprising a vertical cylindrical chamber having a source of combustion gas in the lower portion thereof, a flue at the top, a cylindrical baille having a lower end in the form of a depending cone intermediate the flue and combustion gas source, said baille forming an annular space with the wall of the chamber in its upper portion, a cylindrical reservoir vertically positioned in the upper part of the chamber above the baille, a lower manifold adjacent the bottom of the chamber, heat exchange elements surrounding the chamber and adjacent its inside wall connected to the manifold at their lower extremities and having their upper portions located in the annular space surrounding the baille and connected to the periphery of the reservoir at their upper extremities, a downcomer positioned centrally of the chamber connecting asmsos 3 the reservoir and lower manifold, a fluid inlet to the reservoir, and a vapor outlet therefrom.

4. A boiler construction comprising a vertical chamber having a source of combustion gases in the lower portion thereof, a flue at the top, a baille intermediate the flue and combustion gas source causing outward divergence of the gases leaving the chamber, a cylindrical reservoir vertically positioned and located partially in the upper portion of the chamber and partially in the lo lower portion of the flue, a lower manifold adjacent the bottom of the chamber, heat exchange elements surrounding the chamber and adjacent its inside wall surface connecting the manifold and reservoir, a downcomer positioned centrally of the chamber connecting the reservoir and lower manifold, a fluid inlet to the reservoir, and a vapor outlet therefrom.

JOI-1N W. THROCKMORTON. JOHN S. WALLIS. 

